The dataset provides a comprehensive physiological characterization in response to dehydration of several bryophyte species (16 mosses) collected from (1) Sandia Crest, Albuquerque, NM, USA; (2) Billerica, MA, USA; and (3) Aguagarcía, Tenerife, Spain. The dataset is directly linked to the study by Perera-Castro et al. (2026, New Phytologist, DOI: 10.1111/nph.71206), which highlights the imbalance between atmospheric and moss water potentials under different dehydration states. It consists of two complementary tabular files: (1) a gas exchange dataset describing the response to dehydration (“Gas Exchange Data_Characterization of net CO2 assimilation and transpiration of bryophytes during dehydration”, 2390 x 24), and (2) a pressure–volume dataset describing water relations during dehydration (“Pressure Volume Curves_Characterization of water relations during dehydration of bryophytes”, 1232 x 19). Both tables follow a partially long-format structure, with repeated measurements taken during dehydration for each sample, together with the resulting parameterization of the dehydration curves. Each row represents a replicate of a given species under a specific hydric condition, defined by the variable WC (water content). The datasets include both categorical variables (e.g., species identity, replicate identity, and section of the dehydration curve) and continuous variables describing physiological and biochemical traits such as net CO₂ assimilation rate, transpiration rate, sample water potential, water vapour potential, and resistance of the cell wall/plasma membrane to water loss. Missing values (NA) reflect either data loss (e.g., incomplete pressure–volume curves that do not allow accurate determination of the turgor loss point) or variables that apply only once per replicate, independently of water content (i.e., parameters derived from fitting the dehydration curves for both gas exchange and pressure–volume measurements). Both datasets were obtained from independent samples collected from the same species populations. The fitted relationship between water content and water potential from the pressure–volume curves was applied to the gas exchange dataset to calculate additional parameters (e.g., transpiration or resistance to water loss at the species mean turgor loss point). Data were generated using standardized methods for gas exchange and water potential determination in bryophytes.

This dataset was supported by the Fulbright U.S. Student Program, which is sponsored by the U.S. Department of State and the Spanish Fulbright Commission. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Fulbright Program, the Government of the United States, or the Spanish Fulbright Commission. DA Márquez and FA Busch were supported by the Natural Environment Research Council (grant number NE/W00674X/1).